MOSCOW (Reuters) - Russia's new defense minister fired its top military doctor after at least four soldiers died of pneumonia over the last two months, Russian news agencies reported on Monday.

Russian media said Vyacheslav Novikov, head of the army medical directorate, was dismissed because he failed to implement reforms on time and because of the poor state of health among Russia's soldiers.

"Colonel Vyacheslav Novikov was released from his post as acting head of the chief military medical directorate on an order of Russian Defense Minister General Sergei Shoigu," RIA quoted a ministry statement as saying.

Shoigu replaced Anatoly Serdyukov in November atop the defense ministry and has reshuffled the top brass to consolidate his influence in the military, known for the dismal conditions soldiers serve under.

Itar Tass news agency on Saturday cited a preliminary report by the country's military prosecutor's office as saying that the four soldiers who died of both viral and bacterial pneumonia received proper care while in the military.

The military prosecutor's office, however, said a number of other violations caused their deaths, without giving details.

Russia has been struggling for years to reform its armed forces, which have been dogged by low morale and poor living conditions since the 1991 collapse of the Soviet Union.

Russian President Vladimir Putin has tried to reinvigorate the military's spirit and refurbish its rusting armaments, promising an injection of 21 trillion rubles ($691 billion) into the armed forces by the end of the decade.